Questions tagged [experimental-technique]
filling in the unspecified details of elegant-sounding descriptions of experimental methods.
329
questions
3
votes
1answer
67 views
Taring a digital scale improves precision?
Suppose you need to weight something that weights $x$ in a digital scale that reads a non zero value a when empty. There are two options:
Tare the scale and weight, giving $x \pm \Delta x_1$.
Weight ...
1
vote
1answer
43 views
Collimation issue with an DIY spectrograph
I am trying to make an educational echelle spectrograph using easily available materials, basically in a cardboard box. An echelle grating (36 lines/mm) needs another prism to do a cross dispersion ...
0
votes
0answers
62 views
Could a device witnessing the Free Will Theorem be handheld?
After watching Conway's lectures on free will, I realized that I wanted a device akin to a Magic 8-Ball®, but rather than being influenced by the cosmos, it would be free of surrounding influences. Is ...
0
votes
4answers
52 views
Experiment to show that current leads voltage by 90° in capacitor
I understand that current leads voltage by 90° in capacitor.
How does one show that it is true by an experiment?
0
votes
1answer
23 views
What metrics can be used to quantify underestimation of uncertainties?
Suppose an experiment measures a quantity to be $5 \pm 0.3$ and another measures it to be $9 \pm 0.3$
What metrics can be used to emphasize and quantify the error in the estimation of uncertainties by ...
0
votes
0answers
28 views
AdS/CFT-oriented reviews of experimental techniques?
I am doing a PhD in AdS/CMT. In order to have a better understating of the physics of the systems the correspondence aims to describe, I am looking for accessible reviews or online seminars about the ...
0
votes
0answers
5 views
How to tell which side of a transparent substrate has epitaxial growth?
If someone drops an unmarked sample with a thin film on a transparent epitaxial substrate, what is the easiest way to tell which side has the thin film on it? The substrate itself is also pretty thin.
...
2
votes
0answers
59 views
Wave function collapse for experimental quantum state preparation
Has the John von Neumann projection, or the wave function collapse, been used in the experimental preparation of quantum states? As an illustration, for a pair of EPR-type entangled 2-level atoms
$$|\...
0
votes
0answers
54 views
Experimental examples of how to realize the photon coherent state
As well known in the theory of quantum optics, the photon coherent state is defined by
$$\hat{a}|\alpha\rangle = \alpha|\alpha\rangle$$
where $\hat{a}$ is the annihilation operator. Explicitly this ...
1
vote
1answer
71 views
Distinguish between measuring devices and 'sources of unitary evolution'?
In a quantum optics lab, imagine that we are given with a collection of experimental tools to set-up an experiment on an optical table. This collection could consist of devices like photon detectors, ...
1
vote
2answers
142 views
Why do scientists need to measure extremely small intervals of time?
Why do scientists need to measure extremely small intervals of time? Why is it necessary?
3
votes
2answers
207 views
How is speed measured in the LHC
In this question: "Without the Michelson-Morley experiment, is there any other reason to think speed of light is the universal speed limit?", it is stated in Emilio Pisanty's answer that
From a ...
0
votes
1answer
33 views
Electromagnetic Induction experiment with solenoid
The experiment is as follows
A solenoid is connected to a galvanometer and a magnetised iron rod is passed through it. (the apparatus is not ideal, and there is no zero error in the galvanometer)
I ...
6
votes
1answer
60 views
How do you measure the parity of a particle?
When one looks up elementary particles on Wikipedia, as one of their properties their parity is stated. For example the Proton has parity $+1$, while a Pion has parity $-1$. I understand that you have ...
0
votes
0answers
10 views
Air track acceleration experiment
What can be a major error when we are calculating the acceleration of a matter, using the air track? As shown in the picture, the goal is to measure the acceleration of the matter(M). I will hang the ...
4
votes
2answers
91 views
How do we observe that $\frac{dN}{dt} \propto N$?
I was learning how do derive the radioactive decay formula which starts with the experimental observation that the rate of decay is directly proportional to the amount of isotope present. i.e. $\frac{...
1
vote
1answer
48 views
Accurate method or instrument to measure density of shaving cream foam or whipped cream foam?
I am currently filling a "standard" stainless steel cup of known volume with foam and then I weigh it. Then I calculate density.
This method is pretty messy and I have to be careful about how I fill ...
-1
votes
1answer
45 views
Can a slab with a set of IR torches on it help to prevent blossom freeze in early spring?
Every year there are lot's of problems with blossom freeze caused by sudden drop in temperature of the envirement and cold winds. Can a set of parallel infrared torches have a low drop of intensity ...
1
vote
1answer
30 views
Electron irradiation of an entire isotope mass [closed]
I'm going to post this question in a "goal" and "question" format so it is easier to follow along:
The Goal
I'm planning on running a nuclear physics experiment in which I have an arbitrary mass of ...
1
vote
1answer
50 views
Extracting yields of decays from fits
I'm currently reading various papers on the violation of Lepton Flavour Universality in rare B-decays and I would appreciate some help in understanding the methodology for measuring the ratios in ...
1
vote
0answers
54 views
Normalized superpositions of two, given at will, coherent states
In many papers it is nicely demonstrated how to prepare in laboratory an arbitrary pure superposition of the two CSS states $(|z\rangle + |-z\rangle)$ and $(|z\rangle- |-z\rangle)$ ($z$ arbitrary ...
1
vote
0answers
24 views
Beryllium Neutron Multiplier
We know that Beryllium is used in blankets of Fusion Systems because it is a neutron multiplier. I was wondering that if Beryllium is a neutron multiplier can it be used in the fission process(of ...
2
votes
0answers
53 views
Uncertainty in laser beam width
I have voltage vs position data for the cross-sectional profile of a laser beam, acquired from a photodiode, and I'm trying to find the beam's width and the uncertainty in the width. I was planning to ...
3
votes
1answer
70 views
Plausibility of detecting viruses using optical spectra [closed]
Ok, this is a huge long shot, and I also apologise if this is a poor question (I'm a newbie here...). This doesn't seem to me a strictly perfect fit for Chemistry.SE, Biology.SE, or Photography.SE ...
0
votes
1answer
22 views
How to make laser written waveguides?
I don't know if this is the right place to make such a question, but I have spent a few days trying to get a review or really informative article on how to make Photonic Integrated Circuits by laser ...
0
votes
1answer
22 views
Why do (semi-)conducting materials absorb microwaves at their cyclotron frequency? - Cyclotron Resonance Technique
I am currently studying third year physics - more specifically a solid state course.
It was mentioned that in order to determine the effective mass of an electron in the nearly-free-electron model ...
1
vote
1answer
80 views
Does more and more measurements of $X$ indefinitely improve $\sigma_X^2$?
For a physical quantity $X$, does the standard deviation $\sigma^2_X\equiv\langle X^2\rangle-\langle X\rangle^2$ calculated from $N$ measurements smaller than that calculated from $N^\prime(<N)$ ...
0
votes
0answers
24 views
How to calculate acceleration using ADXL345? [duplicate]
I am trying to measure the acceleration and deceleration of a bike by using an 3 axis accelerometer (ADXL345). I know the formula of calculating acceleration using the $x,y,z$-components with respect ...
0
votes
2answers
80 views
How to heat a gas to ~3000K? [closed]
I'm not much of an experimentalist, but I was wondering if there are any well-known, and relatively straightforward ways of heating gasses to high temperatures (~3000K). Say, I have a sealed ceramic ...
0
votes
0answers
16 views
membrane for a reverse osmosis desalination experiment
We are second year cram schoolers , we are currently working on a project tackling water desalination by reverse osmosis and are required to do an experience. During the process, we encountered some ...
0
votes
2answers
29 views
Deposition of Aluminium Nitride is giving me a range of colors. Why?
I have been trying to deposit Aluminium Nitride via RF Sputtering at certain conditions and the resultant thing I have is a range of colors from blue to brown at the substrate holder. Can anyone ...
26
votes
8answers
6k views
Given fluids expand non-linearly, how were physicists able to make a linear temperature scale?
Materials expand with increase in temperature. As far as I know this property for fluids was put in use to make initial thermometers. We know that expansion of fluid is given by the following formula (...
0
votes
2answers
67 views
Can I have one single molecule of water?
Is it possible detach one single molecule of water into vacuum lab?
1
vote
1answer
110 views
What is the apparatus used in the 1998 Weizmann experiment ..?
Basically what the title says...
For mode context, refer article in the link...
https://www.sciencedaily.com/releases/1998/02/980227055013.htm
I understand that trying [trying: using variable current ...
2
votes
2answers
52 views
What is baking and what are the effects?
In their experiment, Davisson and Germer had to bake the nickel mass because it was oxidized.
What is baking and what does it do to the lattice of the metal?
2
votes
1answer
121 views
+250
Is there an affordable way to create entagled lightbeams?
I have heard it is possible to create entangled laser beams using a process roughly similar to this:
Pass the beam through a crystal that splits each photon into two, each of half the energy of the ...
1
vote
1answer
41 views
Distance between laser diode and photodetector
I have a laser diode with a wide divergent elliptical beam (angles: 57°-13°).
If I want to use a light detector with 50mm diameter, how can I estimate the distance at which I can put the LD from the ...
0
votes
0answers
17 views
Experimental resolution when measuring an oscillatory physical quantity
Say, I want to sample a time-dependent quantity $c(t)$, the experimental resolution of this quantity is limited, denoted as $\delta c$; which means, to my knowledge, that if one wants to distinguish ...
4
votes
1answer
49 views
How to subtract background from many spectra which were taken with different background intensity?
I have two spectra, a spectrum of background signal (let's call it Reference) and measured spectrum consisting of searched signal and background signal. The searched signal is a peak/s with various ...
0
votes
0answers
50 views
How can I create gamma rays with energy >2MeV?
I have been exploring pair production (electron/positron) using gamma, and with a Cobalt-60 source this is easy enough. That's just the problem, though.
I'm looking for a challenge. I want a stream ...
2
votes
2answers
84 views
How could the momentum of a particle be directly measured in experiment?
What could be done in actual experiment to directly measure the momentum of a particle (i.e. without measuring position) in such a way that would collapse the wave function (i.e. reduce the amount of ...
1
vote
0answers
47 views
Linear dependence on photoelectric current
I have done a lab experiment in which we had to determine the Planck's constant through photoelectric effect. The equation reigning this experiment is:
$$eV_c=h\nu-W$$
Where $\nu$ is the radiation ...
1
vote
0answers
45 views
For experiments, how to ensure two photons arrive at beam splitter at the same time?
I'm working on work related DLCZ protocol. In DLCZ protocol, a beam splitter will be settled in the central of two ensembles (you can think it as light source). Ensembles will emit photons ...
3
votes
0answers
203 views
How is a spectrometer is calibrated for intensity?
For the case of spectrophotometers, we can easily calibrate the device(intensity wise) taking the light source inside the device as the reference, without any need of precise knowledge about its ...
1
vote
2answers
60 views
Linear Regressions vs Algebra & Averaging in Solving for a Constant
I'm current taking AP Physics, and in both of the labs performed so far (Snell's Law/Refraction and Galileo's Inclined Plane), I have been trying to calculate some constant from a linear relationship ...
1
vote
1answer
22 views
Would SiPMs respond differently to scintillation light from neutrons vs. gammas?
I have a fast-neutron scintillator which also is sensitive to gammas (much less so, though). When I connect it to a SiPM instead of a PMT, the gamma pulses (obtained from performing pulse shape ...
0
votes
1answer
31 views
Why photodiode measures random phase superpositions on continuous-wave (10kHz) white light?
I measured a 10 kHz modulated white light using a photodiode (Thorlabs PDA10A):
Unexpectedly, the photodiode output sensitively depends on the orientation and position of the photodiode. For two ...
4
votes
3answers
155 views
Does frequency of light change in the LIGO interferometer arms?
There are a number of questions on the internet and on this site asking about how the LIGO interferometer measurement works given that the gravitation wave stretches both the length of the ...
1
vote
0answers
100 views
Initial conditions in QM
My questions are about initial conditions in QM in experiment and in lab.
We consider many different initial wave functions, and we solve the problem on paper. Now, I have 2 questions about this in ...
1
vote
1answer
37 views
Do we need to know Earth's magnetic field locally?
I'm a high school student and in our course we have elements of earth's magnetic field (dip and other stuff) that lets us know the value and direction of magnetic field at any point on the planet.
I ...
